Manufacturing processes of backplane for segment displays
View Patent ↗The present invention relates to design and processes for the manufacture of backplane for segment displays. The process comprises: a) forming conductive lines on a non-conductive substrate layer; b) covering the conductive lines with a photoimageable material; c) forming conductive areas connected to the conductive lines and embedded in the photoimageable material; d) plating a conductive material over the photoimageable material to form segment electrodes; and e) optionally filling gaps between said segment electrodes with a thermal or radiation curable material followed by hardening said thermal or radiation curable material.
1. A process for plugging gaps between segment electrodes in a direct drive display comprising display cells filled with an electrophoretic fluid wherein said electrophoretic fluid comprises charged pigment particles dispersed in a solvent, which process comprises the following steps in sequence:
a) applying a thermal or radiation curable material in a liquid form to the top surface of the segment electrodes,
b) laminating a release film over the top surface to squeeze the material into the gaps between the segment electrodes and controlling the lamination pressure with a nip roller,
c) hardening the thermal or radiation curable material, and
d) removing the release film after hardening of the thermal or radiation curable material.
2. A process for the manufacture of a backplane for a direct drive display comprising display cells filled with an electrophoretic fluid wherein said electrophoretic fluid comprises charged pigment particles dispersed in a solvent, which process comprises the following steps in sequence:
a) forming conductive lines on a non-conductive substrate layer;
b) covering the conductive lines with a photoimageable material;
c) removing the photoimageable material in areas connected to the conductive lines to form open areas;
d) leveling the open areas with a first conductive material to form conductive areas embedded in the photoimageable material;
e) forming segment electrodes by plating a second conductive material over the photoimageable material;
f) applying a thermal or radiation curable material in a liquid form to the top surface of the segment electrodes;
g) laminating a release film over the top surface to squeeze the material into gaps between the segment electrodes and controlling the lamination pressure with a nip roller;
h) hardening the thermal or radiation curable material; and
i) removing the release film after hardening of the thermal or radiation curable material.
3. The process of claim 2 wherein said conductive lines are formed of copper.
4. The process of claim 2 wherein said photoimageable material is a solder mask, negative tone photoresist or positive tone photoresist.
5. The process of claim 2 wherein said photoimageable material is an epoxy-based solder mask.
6. The process of claim 2 wherein said thermal or radiation curable material has more than 85% (w/w) solid content.
7. A process for the manufacture of a backplane for a direct drive display comprising display cells filled with an electrophoretic fluid wherein said electrophoretic fluid comprises charged pigment particles dispersed in a solvent, which process comprises the following steps in sequence:
a) forming via holes on a non-conductive substrate layer laminated or coated with a conductive material on both sides of the non-conductive substrate layer;
b) filling the via holes with a conductive paste;
c) forming segment electrodes on the conductive material laminated or coated on one side of the non-conductive substrate layer and forming conductive lines on the conductive material laminated or coated on the other side of the non-conductive substrate layer;
d) applying a thermal or radiation curable material in a liquid form to the top surface of the segment electrodes;
e) laminating a release film over the top surface to squeeze the material into gaps between the segment electrodes and controlling the lamination pressure with a nip roller;
f) hardening the thermal or radiation curable material; and
g) removing the release film after hardening of the thermal or radiation curable material.
8. The process of claim 7 wherein the via holes are formed by mechanical or laser drilling.
9. The process of claim 7 wherein the conductive paste is carbon paste, copper paste, nickel paste, cobalt paste, silver paste, silver coated copper paste, silver coated nickel paste, silver coated cobalt paste or a composite or alloy paste thereof.
10. The process of claim 7 wherein said thermal or radiation curable material has more than 85% (w/w) solid content.
11. The process of claim 1 , wherein the thickness of the thermal or radiation curable material remaining on top surface of the segment electrode is 0.1 um or less.
12. The process of claim 2 , wherein the thickness of the thermal or radiation curable material remaining on top surface of the segment electrode is 0.1 um or less.
13. The process of claim 7 , wherein the thickness of the thermal or radiation curable material remaining on top surface of the segment electrode is 0.1 um or less.
14. The process of claim 1 wherein the thermal or radiation curable material has a dielectric constant in the range of about 1 to about 10.
15. The process of claim 2 wherein the thermal or radiation curable material has a dielectric constant in the range of about 1 to about 10.
16. The process of claim 7 wherein the thermal or radiation curable material has a dielectric constant in the range of about 1 to about 10.